As recently as the early 1990s, surgical operations for trauma were directed at the anatomic repair of all injuries at time of the initial operation. It was observed during these exercises that many patients became hypothermic, acidotic, and coagulopathic. Patients showing these three signs often died. Death often occurred in the operating room due to exsanguinations, or postoperatively, due to the complications of prolonged shock and massive transfusion to replace blood lost as a result of the trauma.
One of the most notable developments in the recent evolution of surgery has been the introduction of the concept of staged laparotomy to overcome the deficiencies of the repair all-at-once approach. This new strategy of staged laparotomy, employing new tactics that have been termed damage control, is now used in 10% to 20% of all trauma laparotomies.
This damage control strategy opens the way for a variety of new devices and methods for a) control of hemorrhage from solid organs or viscera, b) control of hemorrhage from peripheral wounds and peripheral vascular lacerations, and c) control of contents spillage from hollow viscera. Although there are procedures for controlling these injuries, none of these procedures utilize optimal devices or tactics in their execution. Each area offers technological opportunities to improve the devices and procedures for applying those devices.
Ever since the advent of abdominal surgery, surgeons have relied on the same thinly woven cotton gauze packing pads that are currently in favor. These gauze pads are called laparotomy pads or Mickulitz pads. These pads were designed for use as sponges but not for use as hemostatic tampons. Nonetheless, since World War I, surgeons faced with severe bleeding have relied on packing patients with these sterilizable gauze sponges in an effort to control bleeding. Since World War II, it has been known that abdominal packing using these pads has been associated with abdominal sepsis and re-bleeding after pad removal. Despite these limitations, even today, they are the mainstay of damage control hemostasis.
The specific issues with the gauze pads are that they are porous and allow the free passage of blood through the mesh. Other unfavorable characteristics include the lack of intrinsic coagulation inducing properties. The pads are easily saturated and they do not stick to one another. The pads are capable of promoting infection because they serve as a nidus for bacteria in a contaminated field. They have no intrinsic antiseptic or antimicrobial action. These pads are unsuitable for packing solid viscera because they stick to the visceral wound tissue and cause re-bleeding upon removal. Although generally recognized as sub-optimal, the gauze pads have the advantages of being cheap, familiar and ubiquitous. For these later reasons, they continue to remain the mainstay of damage control hemostasis. Among the opportunities for new technologies and instruments to support the process of damage control, the first requirement is an improvement in the surgical pack and for control of peripheral hemorrhage through an open wound through the skin.
Other current pads for hemostasis include gel-foam, Surgicel, and fibrin sponges. These devices are all liquid permeable and require blood coagulation to occur before impermeability and hemostasis are achieved. In addition, the fibrin sponges are very rigid and will not conform to a wound while in the dry state. Typical examples of the prior art in hemostatic packing systems include U.S. Pat. No. 5,643,596 to Pruss et al., U.S. Pat. No. 5,763,411 to Edwardson et al., U.S. Pat. No. 5,800,372 to Bell et al., U.S. Pat. No. 6,054,122 to MacPhee et al., and U.S. Pat. No. 6,056,970 to Greenawalt et al. These patents, all of which are included herein by reference, disclose permeable hemostatic packing and dressings with topical hemostatic coatings. These devices all serve the purpose of stopping bleeding in underlying vessels with an occlusive backing but the backing is still permeable to blood leakage. The lack of impermeability in these prior art patents is not recognized as an issue.
While hemostatic packing devices are well known in the art, the utility of said packing devices is limited by their propensity to harbor pathogens and their propensity to create re-bleeding by adherence to healing surfaces. One device uses a powdered hemostatic agent that is poured into a wound. The hemostatic agent reacts with the blood, withdrawing water from the blood and causing rapid thrombosis to occur. This agent, however, aggravates the spread of infection and is difficult to remove when definitive repair takes place. The reaction with the blood is exothermic and causes undesirable, localized tissue heating. Further, there is no inherent mechanism to hold the hemostatic agent in place in the wound other than application of a separate covering bandage. In addition, current devices adhere to a wound or surrounding tissue by adhesive methodologies. In an acute or emergency setting there may be profuse bleeding, water, oil, mud, or other contaminants that defeat an adhesive and prevent sticking. Current bandages can control bleeding that weeps from a wound because of pressure restrictions but do not control major vessel hemorrhage because they cannot stop the flow of blood at unrestricted systemic arterial pressure.
New devices, procedures and methods are needed to support the strategy of damage control in patients who have experienced massive bodily injury. Such devices and procedures are particularly important in the emergency, military, and trauma care setting. These new devices rely on the principles of impermeability to blood passage, limited nidus formation for bacteria, the ability to carry prothrombogenic material, and the lack of intrinsic thrombogenicity except by providing a physical barrier or pressure source.